1,720,998 research outputs found
Sull'utilizzo delle talee nelle sistemazioni di versante
No full textNel presente lavoro viene affrontato il tema della valutazione del contributo delle talee alla sistemazione dei versanti. In particolare, viene presentato uno schema di calcolo per valutare il fattore di sicurezza di un pendio in presenza di talee, basato sull’analisi all’equilibrio limite delle forze agenti sul complesso terreno-talea. Lo schema proposto tiene conto sia delle caratteristiche specifiche del versante (pendenza, parametri geotecnici, grado di saturazione), sia delle caratteristiche della specie vegetale utilizzata (numero di germogli radicali, resistenza delle radici, frequenza del diametro), sia dei parametri progettuali (lunghezza delle talee, angolo di posa, spaziatura longitudinale e trasversale). Lo schema sviluppato è stato applicato utilizzando le caratteristiche biotecniche di talee di Salice rosso (Salix purpurea L.) misurate nell’ambito di una sperimentazione eseguita presso il vivaio dell’Azienda Regionale delle Foreste della Regione Lombardia situato a Borno (BS). I risultati ottenuti dall’applicazione mostrano un buon accordo con i valori dedotti da Schuppener (1999) mediante prove dirette di sfilamento di piantine radicate. I risultati ottenuti mostrano altresì un consistente effetto di rinforzo esercitato dalle talee, che si dimostra determinante per mantenere il fattore di sicurezza oltre l’unità
Identification and Analysis of Natural Channel Networks from Digital Elevation Models, Earth Surface Processes and Landforms
No full textQuaderni di Idronomia Montana
No full textIl libro raccoglie contributi in tema di sistemazioni idraulico-forestali cercando di dare rilievo alle soluzioni di sistemazione dei dissesti nella rete idrografica e nei versanti che privilegiano l'utilizzo di tecniche di ingegneria naturalistica. Particolare attenzione viene data alla scelta metodologica delle tecniche di ingegneria naturalistica alla luce di una crescente richiesta di sostenibilità ambientale degli interventi
Determinazione distribuita del contributo di versante al trasporto solido in sospensione in bacini alpini
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Exploring correlation between stand structural indices and parameters across three forest types of the southeastern Italian Alps
Full text linkForest stand structure can be described through stand structural parameters as well as using stand structural indices. However, to date, there is still much uncertainty regarding how stand structural indices and parameters are intercorrelated. The analysis of correlation can guide their selection in research applications and forest management, avoiding redundancies and loss of time during data collection. In this study, using a sample of forest stands belonging to three forest types of the southeastern Italian Alps, we explored the correlation among stand structural indices, and then we checked the relationships between stand structural indices and stand structural parameters. The results indicate that the stand structural indices vary among the sampled forest types. Moreover, the correlation among stand structural indices indicates that some of them are strongly intercorrelated and, thus, they can give redundant information. Strong correlations have been found between the Shannon index and the Mingling index, between the Gini index and the Diameter differentiation index, and between size dominance indices. Correlations between stand structural indices and stand structural parameters were weak, and, therefore, we cannot recommend the exclusive use of stand structural indices as alternative to the common stand structural parameters. Instead, the combined use of stand structural indices and parameters can be a robust solution for describing forest stand structure
The ability of tree stems to intercept debris flows in forested fan areas: A laboratory modelling study
Full text linkDebris flows are one of the most common geomorphic processes in steep mountainous areas. The control of their propagation on alluvial fans is fundamental; valley bottoms are usually characterised by high damage potential because they contain concentrations of inhabitants and infrastructure. It is well known that forests have a protective function in that they reduce the triggering of debris flows, as well as hinder their motion and promote deposition, but a quantitative assessment of these effects is still lacking. Using laboratory experiments that simulate debris-flow depositional processes, this research investigated the ability of forests to reduce debris-flow runout and depositional area. The experiments considered two different forest types, high forests and coppice forests, and four volumetric concentrations of sediment (0.50, 0.55, 0.60, and 0.65). The results confirmed that the sediment concentration of the flow is a key factor in determining the geometry of the deposits. On the other hand, forests can reduce debris-flow runout distance and, in general terms, affect the characteristics of their deposits. The results showed that vegetation appear to reduce debris-flow motion especially when the debris-flow kinematic load at the fan apex is low. About the sediment concentration of the mixture, high forest did not exhibit a clear behaviour while coppice forest appears to promote significant deposition at all of the tested concentrations, and this effect increases with the solid concentration (reductions in runout between approximately 20% and 30% at CV=0.50 and CV=0.65, respectively, were observed). Due to their higher tree density, in fact, coppice forests seem to have a better protective effect than the rigid trunks of high forest trees. For this last type of forest, a relationship between the H/L ratio, which represents energy dissipation, have been found and compared with the scenario without forest
L'impiego dell'Ingegneria naturalistica nella pratica professionale - Resoconto della Tavola rotonda
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